Describe the problem

If you set the network.proxy key (e.g., via the "Network" tab of the Arduino IDE preferences dialog), then during a later IDE session try to disable the proxy preference, Arduino CLI continues to attempt to connect to the Internet via a proxy.

To reproduce

1. Select File > Preferences... from the Arduino IDE menus.
2. Select the "Network" tab from the "Preferences" dialog.
3. Select the radio button next to "Manual proxy configuration".
4. Click the "OK" button.
5. Select File > Quit from the Arduino IDE menus.
6. Start Arduino IDE.
7. Select File > Preferences... from the Arduino IDE menus.
8. Select the "Network" tab from the "Preferences" dialog.
9. Select the radio button next to "No proxy".
10. Click the "OK" button.
11. Select File > Quit from the Arduino IDE menus.
12. Start Arduino IDE.
13. Select File > Preferences... from the Arduino IDE menus.
14. Select the "Network" tab from the "Preferences" dialog.

🐛 The "Manual proxy configuration" radio button is selected.
🐛 When Arduino CLI attempts to download resources from the Internet, an error like "proxyconnect tcp: dial tcp: lookup _: no such host" occurs.

Expected behavior

It is possible to disable the proxy after enabling it.

Arduino CLI version

0.29.0

Operating system

• Linux
• Windows

Operating system version

• Windows 11
• Debian Bullseye

Additional context

The network.proxy key in ~/.arduinoIDE/arduino-cli.yaml is set to http://_/

Workaround

1. Select File > Quit from the Arduino IDE menus if it is running.
2. Use any text editor to open the file at the following path:
   • Windows:

     C:\Users\<username>\.arduinoIDE\arduino-cli.yaml
     

     (where <username> is your Windows username)
   • Linux:

     ~/.arduinoIDE/arduino-cli.yaml
     

     ❗ The ~/.arduinoIDE/ folder may be hidden by default in your file manager and terminal.
   • macOS:

     ~/.arduinoIDE/arduino-cli.yaml
     

     ❗ The ~/.arduinoIDE/ folder is hidden by default. You can make it visible by pressing the Command+Shift+. keyboard shortcut.
3. Delete the lines from the file that have this format:

   network:
     proxy: <some proxy URL>
     user_agent_ext: daemon

4. Save the file.
5. Start the Arduino IDE.

You should now find that "No proxy" is selected in the "Network" tab of the "Preferences" dialog.

Additional reports

• not recoverable PROXY Settings arduino-ide#1363
• https://forum.arduino.cc/t/cannot-install-library-with-arduino-ide-2-0-3/1077981
• https://forum.arduino.cc/t/boards-and-libraries-fail-to-load-update/1052539
• https://forum.arduino.cc/t/newbie-unknown-proxy-host-blocking-the-install-of-libraries/1050777
• https://forum.arduino.cc/t/ide-2-0-4-on-win10-shows-no-ports-for-digispark-usb/1083255
• https://forum.arduino.cc/t/json-no-such-file/1119208/10
• https://forum.arduino.cc/t/arduino-ide-2-0-3-can-not-start/1160370

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the nightly build
• My report contains all necessary details